Device and method for detecting small quantities of light, comprising an electronic image converter embodied in semiconductor technology

Abstract

The invention relates to a device for detecting small quantities of light, comprising an electronic image converter embodied in semiconductor technology for detecting the photons representing the small quantities of light and an electronic circuit connected to the electronic image converter for reading the electronic image converter and for generating a signal representing the number of photons received by the electronic image converter, wherein the electronic image converter comprises at least 100,000 light-sensitive cells and the electronic circuit is adapted to add together the signals coming from light-sensitive cells placed on the electronic image converter.

The invention claimed is: 
     
       1. A device for detecting small quantities of light, comprising a first CCD or CMOS electronic image converter having a large number of light-sensitive cells for detecting photons representing the small quantities of light and for supplying a readout signal, and a processing circuit for processing the readout signal to a measurement signal representing the quantity of received photons, wherein
 the device comprises at least one second electronic image converter which is the same as the first electronic image converter and which is shielded from light; 
 the processing circuit is also connected to the second electronic image converter and is adapted to compensate the readout signal of the first electronic image converter with a readout signal of the second electronic image converter; 
 the first and the second image converters are thermally closely coupled to each other; and 
 for each image converter, readout signals coming from any of the light sensitive cells of said image converter are respectively added together either by the processing circuit or by said image convertor for an adjustable period of time. 
 
     
     
       2. The device as claimed in  claim 1 , wherein the first and the second image converters are placed in the vicinity of each other. 
     
     
       3. The device as claimed in  claim 1 , wherein the light-sensitive cells present on each of the first and the second image converter are divided into a measurement group and a reference group, that the reference group is shielded from light and that the processing circuit is adapted to compensate readout signals of the light-sensitive cells belonging to the measurement group with readout signals of light-sensitive cells belonging to the reference group. 
     
     
       4. The device as claimed in  claim 1 , wherein the device comprises a third electronic image converter which is the same as the first and the second electronic image converters and which is adapted to receive light signals functioning as comparison;
 that the processing circuit is also connected to the third electronic image converter and is adapted to compare the readout signal of the first electronic image converter to the readout signal of the third electronic image converter; and 
 that the first, second and third electronic image converters are thermally closely coupled to each other. 
 
     
     
       5. The device as claimed in  claim 4 , wherein the first, the second and the third electronic image converters are placed in the vicinity of each other. 
     
     
       6. The device as claimed in  claim 4 , wherein the light-sensitive cells present on the third image converter are divided into a measurement group and a reference group, that the reference group is shielded from light and that the processing circuit is adapted to compensate readout signals of the light-sensitive cells belonging to the measurement group with readout signals of light-sensitive cells belonging to the reference group. 
     
     
       7. The device as claimed in  claim 1 , wherein the device is provided with positioning means for positioning a carrier so that light emitted by light-emitting elements placed at a first position on the carrier reaches the first electronic image converter while excluding other light. 
     
     
       8. The device as claimed in  claim 7 , wherein the positioning means are adapted to position a carrier so that light emitted by light-emitting elements placed at a second position on the carrier reaches the third electronic image converter while excluding other light. 
     
     
       9. The carrier for carrying light-exciting samples, wherein the carrier is adapted to be positioned by the positioning means as claimed in  claim 8 . 
     
     
       10. A carrier for carrying light-exciting samples, wherein the carrier is adapted to be positioned by the positioning means as claimed in  claim 7 . 
     
     
       11. The carrier as claimed in  claim 10 , wherein the carrier is adapted to add at least a first reagent to the sample and that the first reagent is adapted to form a first light-emitting element together with cells of disease-causing micro-organisms present in the sample. 
     
     
       12. The carrier as claimed in  claim 10 , wherein the carrier is adapted to add at least a second reagent to the sample and that the second reagent is adapted to form a second light-emitting element together with cells of disease-causing micro-organisms present in the sample. 
     
     
       13. A method for detecting light-emitting elements present in a carrier, comprising the steps of mutually defined positioning of the carrier and a first electronic image converter, detecting the light emitted by the light-emitting elements present in the carrier, reading the first electronic image converter with a processing circuit connected to the first electronic image converter, and generating a first signal representing the number of photons received by the first electronic image converter within a period of time, wherein the first signal is compensated with a second signal coming from a second electronic image converter which is the same as the first electronic image converter and is shielded from light, but thermally closely coupled to the first electronic image converter. 
     
     
       14. The method as claimed in  claim 13 , wherein a biological sample is arranged on the carrier, the biological sample is brought into contact with a first reagent and a second reagent, that the combination of the first biological sample and the first reagent forms first light-emitting elements which are positioned relative to the first electronic image converter, and that the combination of the biological sample and the second reagent forms second light-emitting elements which are positioned relative to a third electronic image converter, and that the first signal and a third signal coming from the third electronic image converter are compensated with the second signal coming from a second electronic image converter which is the same as the first and third electronic image converters and is shielded from light, but thermally closely coupled to the first and third electronic image converters.